Cabinet construction



Feb. 2, 1965 J. G. BRYSQN 3,167,931

CABINET EONSTRUCEION Filed Aug. 22, 1963 2 Sheets-Sheet 1 IZiIIZ FIG. :3

vINVENTOR.

JAMES 6. BRYSQN.

ATTORNEY.

J. G. BRYSON CABINET CONSTRUCTION Feb. 2, 1965 2 Sheets-Sheet 2 FiledAug. 22, 1963 INVENTOR. JAMES G. BRYSON.

FIG. 6

loam ATTORNEY.

United States PatentfOiliCe 3,157,931 Patented F 2, 1965 3,167,931CABINET CGNSTRUCTION JamesG. BrysonTyler, Tex.,-assignor to CarrierCorporation,- Syraeuse, N.Y.,-a corporation of Delaware FiledAug. 22,19:53am No. 303,811 6 Claims. (Cl. 62-373) This invention relates-tocabinets, and, more particularly,- it relatesto facilitating the openingof the acwss door to a cabinet such as a refrigerated cabinet.

Refrigerated-cabinets generally comprise a-box section having.anaccess-opening covered by a hing'edly mounted access door. hisfrequent practice to provide an airtight seal between the access doorand the box section by means of asuitable gasket which is often of themagnetic type. Such gaskets usually have a firsted'ge portion fixedlysecured to one ofthe members such as the access door, a second edge.portion :which carries one or more magnets designed to temporarilysealingly'en'gage the second edge portion to a metal flange on the boxsection, and an extensible web portion between the first and second edgeportions of the gasket. The extensible web portion allows the gasket toaccommodate itself to the shape of the access opening ofrtherefrigerator box and to the clearance which exists. between'the' box andthe access'door sections. The extensible Web portion of the gasket isalso desirable because the portioniof the access door closest to 'thehinges may approach the access opening of the "box section more closelythan the portion of the door remote from the hinges. This type ofconstruction'has found Wide application in household refrigerators;including food freezers and frozen food storage cabinets. Refrigeratorsof this type are usually also provided with a'rigid handle on the accessdoor which the user-pulls to break the adhesion between the magneticportion of the gasket andthe box section in order to gain access to therefrigerator.

Even though the force exerted by the magnetic gasket tending to maintainthe refrigerator door closed is relativelysm-a-ll, users often complainthat an excessive pull is-required in order to open the access door.This prob lem is particularly acute with low temperature refrigeratorssuch as food freezers and arises for-two reasons. First, when therefrigerator door is opened and then closed, ambienta-ir at roomtemperature escapes into the interior of-the box-section. Thisrelatively warm air is rapidly cooled'in the interior of therefrigerator after the door is closed. As the air inside therefrigerator is cooled, it is reduced in volume giving rise to amaterially lower pressure inside the refrigerator than that of theambient air on the exterior of the door. This difference in pressureacross the access door result in a force tending to keep the doorclosed, which must be overcome in order topull the door open. It'hasbeen found'that for a typical household freezer, having an interiortemperature of about F., the difference inpressure across the accessdoor due to the cooling of warm air admitted into the box section may beon the order of about two inches of water. I Such a refrigeratortypically has a door area of about thirteen square feet and,consequently, this difference in pressure may result in a force of aboutthree hundred pounds tending to keep the door closed. This force,tending to oppose opening of the door, Will exist until the pressuresare equalized by leakage of ambient air into the refrigerator, which maytake several minutes or longer. The user may find, -therefore, that itis exceedingly dithcult or impossible to reopen the door for a period oftime after it has been closed. Second, as the user initially pulls onthe door handle to open the door, the expansibleWebporti-onofthe'gas'ket extends sufficiently to slightly increase the internalvolume of the refrigerator. Even though the pressures across the doorare equal, thi increase in internal volume of the refrigerator resultsin a specification and attached drawings, wherein:

the magnetic pull exe'rted by the gasketwhich' is relatively nominal,but must also overcome the force tending to keep the door closed byreason of the pressure difference across the door due to the'diiferencein'i-ntern'al and external'pressures acting on the door.

'Itis therefore the principal object of this invention to facilitate theopening ofa cabinet door.

It is a further object of this inventionto' pnovide a means and methodfor reducing the difference in pressure across a cabinet door so as tofacilitate opening thereof.

It is a further object of this invention to provide a means'foradmitting ambient air into the interior of a refrigerated enclosure uponthe occurrence of an excessively great pressure difference tending toresist opening of its accessd-o'or.

It is a still further object of this invention-to provide an improvedcabinet construction.

These and other objects of this invention are achieved in theillustrated preferred embodiments thereof by providingtarefrigerator'cabinet, such'as a frozen food-storage" compartment, havingvalve means responsive to a predetermined pressure difference betweenthe interior and the exterior of'lthe cabinet. The valve means serves toadmit ambient air into the interior of the cabinet to prevent anexcessive pressure difference from occurring across'the access door.

'In one embodiment of this invention the valve isdisposed inthe accessdoor section of' the ref-rigeratedenclosure and is'disposed on the outerWall thereof'so that the valve is warmed by. ambient air to prevent theaccumulation offrostthereon which might-cause malfunction in theoperation of the-valve. In another embodimentof this invention the valveis located inthe cabinet section of the refrigerated enclosure and-meansmay be provided to supply'heat-to the valve from the hot gas-line of therefrigeration system to maintain th'e temperature of the valvesufficiently high to prevent moisture fromfreezing thereon. I n

The Iforegoingand other objects of this invention will become moreapparent by. reference to the following FIGURE -1 is a fragmentarycross-sectional view through a lpohtion of'ref'rigera'ted cabinetembodying the instant invention;

FIGURE 2 is 'a cross-sectional view through the valve shown inFIGURE 1;

FIGURE 3 is a planvi'ew'looking downwardly onthe valve slr wn'inFIGURE1;

FIGURE '4 is a fragmentary view, partly broken away and incross-section, of a refrigerated enclosure utilizing another embodimentof applicants invention;

FIGURE Sisa fragmentary cross-sectional view showingthe'detailorthevie'w illustrated in'FIGURE 4; and

FIGURE'6 is a plan'view of the valve Shown in FIG- URE 5.

'outer'wall-including a metal flangediportion 12 defining v anaccessopening to the interior of the cabinet.

floor to support the refrigerator. Suitable inner wall members 14 andilcooperate with outer wall 121to form a double wall construction for thereception-of insulation 16. A refrigerator shelf 17 is provided in theinterior of box section 11 and may be cooled by tubes 18 which form partof the evaporator of a conven A gasket or sealing means 25 is providedto make a Box: section 11 is provided with a base 13 which rests on-the29.. When this difference in pressure-exceeds the pressure at whichcheck valve 32 opens, additionalambient air is automatically admittedinto the interior of the refrigerator through check valve 32 and ventpassages 33, 34, so as to increase the"pressure,,-in the interior of box11. By designing check valve 32 to open at a suitably low pressuredilference,.t he corresponding difference in internal and externalpressures across door2tl may be reduced to an extent that only a smallforce is necessary to open the door. Likewise as the user begins to opendoor 20 and the pressure inbox 10 is reduced by expansion of gasket25,.check valve 32 admits additional amsubstantially'airtight sealbetween access door section 2-0 and box section 11 when the door is in aclosed position. Gasket suitably comprises a first edge portion'zd whichis fixedly secured to outer wall 23 of access door section 29 by one ormore sheet metal screws 27. Gasket 25 hasa second edge portion 28carrying magnetic means 29 such as a magnet which is ,attractedto metalflange 12.

to make temporary relatively airtight engagement with box section 11. Anextensible imperviousweb portion 30 extends between first edge portion26 and second edge portion 28 of gasket 25. Extensible portion 30compensates for any non-uniformity in the distance between access door26 and box 11 and permits the gasket to adapt itself to'the shape of thecabinet with which it is used. a

This cyclic fluctuation may produce a pressure difference In accordancewith this invention a check valve 32 extends through. outer wall 23 ofone of the members such .as access door 20. A suitablevent passage 33 isprovided through insulation 24. One or more suitable vent passages 34are provided through inner wall 22 of access door 20.

Ventpassage 34 is preferably provided at a location on door 29 that isof relatively high temperature, above the dew point of the ambient air,andis desirably at a location which is above 32 R, if possible, so thatthe vent passage will not become clogged by ice formation due tocondensation of moisture from the air in contact therewith.

It will be appreciated that in the location shown valve 32 is in heatexchange relation with, and receives heat from the relatively warmambient'air to assist in pre venting frost formation thereon. Othermeans, such as those to be subsequently described may be .used to supplyheat to valve 32, if desired.

by heat sealing or riveting at 38. to base member 35.

Diaphragm member 37 may be provided with a slightly 'bossed peripheraledge portion 39 to make sealing .en-,

gagement about the contacting edge of base member 35. It has been foundthat for the purposes of thisinvention diaphragm member 37 may suitablyhave suificient flexi- A flexible plastic bient air'into the interior ofthe'box to facilitate the open ing of the door. Using the examplepreviously discussed, valve 32 may open at a pressure difference ofabout /2 lb. per square foot thereby limiting the force due to thepressure difference across a thirteen square foot door to only about 6/2 lbs. Consequently, the force required to open the door is limited toonly 6 /2 lbs. morethan that normally required toovercomethe force ofattraction of the magnetic gasket.

It will be appreciated that a permanently open vent passage could beemployed to-equalize the pressures between the interior and exterior ofthe cabinet. This solution, however, is not satisfactory because in thecase of a refrigerated enclosure there is a measurable pres surefluctuation due to cycling of the refrigeration equipment from anoperating to a non-operating condition.

across the door on the order of +.O2 to '.05 inch of water. If apermanently open vent passage were provided from the exterior into theinterior. of box 10, a considerable amount of cooled air would escapefrom the box when'the refrigeration equipment cycled on and aconsiderable amount of warm air wouldbe admited to the box each time therefrigeration equipment cycled on. This loss of refrigerated air andintake'of warm air would undesirably require providing increased coolingcapacity and would result in poor control of temperatures in therefrigerated enclosure. To prevent this, applicants valve is arranged sothat a minimum pressure difference greater than that normallyexperienced due to cycling of the refrigeration equipmentis necessarybefore'checkvalve 32 opens.

Referring now particularly to FIGURE 4, there is shown another.embodiment of applicants invention as applied to a typical householdrefrigerator, suchas afrozen food bility so that a pressure differenceof approximately A0 inch of water, which is equivalent to about /2 lb."per square foot pressure, acting on the underside thereof,

'as shown in FIGURE 2, is sufficient to open the-valve.

Preferably, valve 32 is located on theunderside of I the exteriorsurface of door 20 so that it is concealed from view but is exposed tothe heat of theambientajr therer r storage compartment or freezer. Inthis embodiment, refrigerator 45 is provided with a box section 46.having an access'opening therein which isv closed by an access doorsection 47' and gasket 48, similar to that described with reference tothe preceding embodiment of this. invention. A suitable rigid handle 49is provided to open door .47. A compressor: 59 having a hot gas line 51leading to a condenser 52 ismountedon the exte ior of box section .46as'shown in'the drawing. Evaporator tubes 53 of the refrigeration systemaredisposed beneath shelf 54' to cool the interior of the refrigerator.Box section 46 has an inner wall 669 and an outer'wall 61 between whichis disposed insulation 62. p

An opening 65, which may have a suitable grommet about it, is formed ininner wall so of box section 46 and connects witha vent passage 63through insulation 62. In order to prevent the entrance of moisture'intoinsulation'material 62 a wax or other coating 64 is preferably appliedabout the periphery of vent passage 63. A valve assembly 66 is securedby fastening means 7% about a suitable opening formed in outer wall 61connecting with vent passage 63. p

Valve assembly 66 comprises a base'member 67 which may be of metal orother material having one or more ports 71 formed therein. A flexiblediaphragm 68, which may be formed of plastic'or metal, is secured bysuitable means 69 to base member 67. As in the preceding embodiment,valve 66 is preferably designed to operate at F '3 a suitably low.pressure difference such as /2 lb. per square foot difference inpressure so as to facilitate opening of door 47- by admitting ambientair into the interior of box 46. On the other hand, valve 66 is alsodesigned as in the preceding embodiment so that it will not normally beopenedby the differences in pressure encountered by cycling of therefrigeration system, so as to prevent unwarrantedreductionin controlandelfective capacity of the refrigeration system. It will also beapparent that valve 66, like valve 32 previously described, is a checkvalve which operates in only one directionso that air may be admittedinto box 46. but is 'not permitted to escape from the box to theexterior.

Means are provided to supply heat to valve 66' in order to preventmalfunction of the valve due to ice formation about it. As shown inFIGURE 5, the means to heat valve 66 may comprise hot gas line 51leading from compressor 50 to condenser 52 placed in heat exchangerelation with the valve. In effect, heat absorbed by evaporator coil 53from the box is rejected from 'hotgas line 51 to supply the heatrequired to keep valve 66 above the freezing point or at least above thedew point of both ambient air and the air contained in box 46. Thiseffectively prevents the condensation of moisture on valve 66 andeliminates ice formation thereon which might otherwise prevent properoperation of the valve. Y

Other methods of heating valve 66may be employed, if desired, and asillustrated in FIGURE 4, the valve may be placed'in heat exchangerelation with the relatively warm compressor 50 or condenser, 52,'aswell as hot gas line 51 in order to' achieve the desiredheating. It willbe appreciated that in a particular situation, any one of these means ofsupplying heat to valve 66 or any combination of them may be employedthereby enabling considerable flexibility in the location of the valve.In many situations the heat of the ambient air alone may be sufficientto maintain the valve above the desired temperature so that additionalheating means is not required.

Many modifications and embodiments of this invention will be readilyperceived from the foregoing description. For example, the valve memberemployed may be of the ball and seat variety rather than being of theflapper valve type as shown in the drawings. The entire valve may, ifdesired, be made of plastic or other material and may be located at anysuitable point on either the box or door section. In addition, while theinvention has been de scribed with reference to a refrigeratedenclosure, other applications can be envisioned to reduce the forcerequired to open the access door, an enclosure or other device whetheror not a gasket of the type herein described is employed. It ispreferred, however, to use a valve which senses a pressure differencebetween the exterior and interior of the cabinet with which it isemployed, and automatically opens to admit ambient air therein upon theoccurrence of a pressure exceeding a predetermined maximum desiredpressure which is below that which gives rise to an inconveniently highforce necessary to open the door.

Accordingly, other embodiments, modifications and applications of thisinvention within the scope of the following claims will become apparentto those skilled in the art.

I claim:

1. A refrigerated cabinet comprising:

a box section having means defining an access opening therein,

an access door section adapted to substantially close said accessopening,

said cabinet including sealing means providing a seal between saidaccess door and said box section to substantially prevent the passage ofair between the interior and exterior of said box section when saidaccess door is closed, said sealing means comprising a gasket secured toone of said sections, said 6 gasket having magnetic means associatedtherewith to retain it in sealed. engagement with the other of saidsections, said gasket including an expansible web portion tending toinitially increase the internal volume of said cabinet upon attempting.to open said access door, a refrigerationsystem associated with saidcabinet to refrigerate the interior thereof, and a pressure operatedcheck valve associatedwith said cabinet, said' check valve,

being disposed at a location on said cabinet such that it normallyreceives sufficient heat to inhibit the accumulation offrost thereon, sothat the operationof said valve is not normally. impaired by frost, and

being constructed so as to automatically open in response to apredetermined differencein pressure between the interior and theexterior of said cabinet, thereby facilitating the opening of saidaccess door by, admitting ambient air into said cabinet to prevent apressure difference from existing'across saiddoor in' excess of saidpredetermined difference caused by an initial increase in volume of saidcabinet due. to expansion of said gasket'uponattemptin'g to open saiddoor.

2. A refrigerated'cabinet as defined in claim 1 wherein said check valveis designed to open at a pressure greater than the differences inpressure across said door due to cycling of the refrigeration systemandless than a predetermined maximum pressure across said door whichwould give rise to an excessively high force opposing opening of saiddoor.

3. A refrigerated'cabinet comprising:

a box section having means defining an accessv opening therein, anaccess door section adapted to substantially clos said access opening,

said cabinet including means providing a seal between said access doorand said box section to substantially prevent the passage of air betweenthe interior and exterior of said box section when said access door isclosed, and

a pressure operated check valve associated with one of said sections,said valve comprising:

a ported base member disposed between the interior and exterior of saidcabinet,

a diaphragm member secured to said base and covering the port in saidbase member on the side of said base member adjacent the interior ofsaid cabinet, said diaphragm being flexible and arranged to flex awayfrom said base to uncover said port and to admit air automatically intosaid cabinet upon the occurrence of a predetermined difference inpressure between the exterior and the interior of said cabinet, so as tofacilitate opening of said access door.

4. A refrigerated cabinet comprising:

a box section having an access opening therein;

an access door section adapted to close said access opensaid cabinetincluding means adapted to provide an air seal between said accessopening and said access door;

cooling means including a refrigeration system disposed so as to coolair in said cabinet;

valve means automatically operable upon the existence of a pressuredifference in excess of a maximum desired difference in pressure betweenthe interior and the exterior of said cabinet, for admitting air intosaid cabinet to reduce the pressure difference to a pressure notexceeding said maximum desired pressure difference;

means to supply heat from a portion of said refrigeration system to theregion of the location of said valve means to reduce impairment of theoperation of said valve by inhibiting the accumulation of frost thereon;

and i said means to supply heat from said refrigeration system to theregion of the location of said valve means comprising a compressor ofsaid refrigeration system disposed in heat'exchange relation with saidvalve means. 5. A refrigerated cabinet comp'ring: I a box section havingan access opening therein; an access door section adapted to close saidaccess opens; said cabinetincluding means adapted to provide an air sealbetween said access openingand said access door; cooling means includinga refrigeration system disposed so as to cool air in said cabinet; valvemeans automatically operable upon the existence of a pressure differencein excess of a maximum desired difference in'pressure between theinterior and the exterior of said cabinet, for admitting air into saidcabinet to reduce the pressure difference to a pressure not exceedingsaid maximum desired pres sure difference; I means to supply heat from aportion of said refrigeration system to the region of the location ofsaid valve means to reduce impairment of the operation of said valve byinhibiting the accumulation of frost thereon; and said means to supplyheat from said refrigeration system to the region of the location ofsaid valve means comprising a condenser of said refrigeration systemdisposed in heat exchange relation with said valve 7 means. I 6. Arefrigerated cabinet comprising: a box section having an access openingtherein;

an access door section adapted to close said access opens; 7 saidcabinet includingmeansadapted to provide'an air seal between saidaccessopening andsaid access door; cooling means including arefrigeration system disposed so as to cool air in said'cabinet; i V v ei valve means automatically operable upon theexistence of a pressuredifference in excess of a maximum desired difference in pressure betweenthe interior and 10 the exterior of said. cabinet for admitting air intosaid cabinet to reduce the pressure difference to a pressure notexceeding saidmaximum desired pressure difference; 7 means to supplyheat from a portion of said refrigeration system to the region of thelocation of said valve means to reduce impairment of'the operation ofsaid valve by inhibiting the accumulation of frost thereon; and a r saidmeans adapted to provide an. air seal comprising a gasket secured to oneof said sections, said gasket having magnetic means associated therewithto retain it in sealedengagement with the other'of said sections, saidgasket'including'an expansible web portion tendingto initially increasethe internal volumeof said cabinet upon opening of said access door.

References, Cited by-theExaminer UNITED STATES PATENTS 2,135,091 11/38-Newill O 62-275 0 2,774,116 12/56 Vv'olverton 9887 1/58 'Hobbs a 9887RGBERT A..OLEARY,' Primary Examiner. V

WILLIAM J. WYE, Examiner.

3. A REFRIGERATED CABINET COMPRISING: A BOX SECTION HAVING MEANSDEFINING AN ACCESS OPENING THEREIN, AN ACCESS DOOR SECTION ADAPTED TOSUBSTANTIALLY CLOSE SAID ACCESS OPENING, SAID CABINET INCLUDING MEANSPROVIDING A SEAL BETWEEN SAID ACCESS DOOR AND SAID BOX SECTION TOSUBSTANTIALLY PREVENT THE PASSAGE OF AIR BETWEEN THE INTERIOR ANDEXTERIOR OF SAID BOX SECTION WHEN SAID ACCESS DOOR IS CLOSED, AND APRESSURE OPERATED CHECK VALVE ASSOCIATED WITH ONE OF SAID SECTIONS, SAIDVALVE COMPRISING: A PORTED BASE MEMBER DISPOSED BETWEEN THE INTERIOR ANDEXTERIOR OF SAID CABINET, A DIAPHRAGM MEMBER SECURED TO SAID BASE ANDCOVERING THE PORT IN SAID BASE MEMBER ON THE SIDE OF SAID BASE MEMBERADJACENT THE INTERIOR OF SAID CABINET, SAID DIAPHRAGM BEING FLEXIBLE ANDARRANGED TO FLEX AWAY FROM SAID BASE TO UNCOVER SAID PORT AND TO ADMITAIR AUTOMATICALLY INTO SAID CABINET UPON THE OCCURRENCE OF APREDETERMINED DIFFERENCE IN PRESSURE BETWEEN THE EXTERIOR AND THEINTERIOR OF SAID CABINET, SO AS TO FACILITATE OPENING OF SAID ACCESSDOOR.